package s_2

import (
	"fmt"
	"sync"
)

var m *Manager
var lock *sync.Mutex = &sync.Mutex{}

func GetInstance() *Manager {
	lock.Lock()
	defer lock.Unlock()
	if m == nil {
		m = &Manager{}
	}
	return m
}

type Manager struct {
}

func (p Manager) Manage() {
	fmt.Println("manage...")
}
